1. Field of the Invention
The present invention relates a heat exchange unit, which comprises a plurality of heat transfer members, which are formed of a metallic thin sheet and combined in parallel and integrally with each other, and especially to such a heat exchange unit in which heat exchange fluid having a high pressure can be introduced between the heat transfer members.
2. Description of the Related Art
If there is a wish that heat transfer coefficient is increased to enhance heat exchange effectiveness, utilizing a heat exchanger by which heat exchange is made between a high temperature fluid and a low temperature fluid, a plate-type heat exchanger has conventionally been used widely. The plate-type heat exchanger has a structure in which a plurality of heat transfer members having a plate-shape are placed parallelly one upon another at prescribed intervals so as to form passages, which are separated by means of the respective heat transfer member. A high temperature fluid and a low temperature fluid flow alternately in the above-mentioned passages to make heat exchange through the respective heat transfer members. Japanese Laid-Open Patent Application No. S53-56748 describes an example of such a conventional plate-type heat exchanger. FIG. 8 is a cross-sectional view illustrating a schematic structure of the conventional heat exchanger.
The conventional heat exchanger 100 as shown in FIG. 8 is composed of a main body 101, a pair of separation walls 102 disposed vertically in the main body 101, a plurality of plate-shaped heat transfer members 103 placed between the pair of separation walls 102, a plurality of spacers 104 for keeping the heat transfer members 103 at prescribed intervals to form passages 110, and a pair of partition walls 105 for supporting the heat transfer members 103 and the spacers 104 to define independent passages for flow of heated fluid and non-heated fluid, respectively.
In general, the heat transfer member 103 used in the conventional plate-type heat exchanger having the above-described structure has a predetermined pattern of irregularity, which serves as a heat transfer face having the opposite surfaces with which heat exchange fluids are to come into contact. The heat transfer member 103 having such a predetermined pattern of irregularity has usually been put into practical use by subjecting a metallic thin sheet to a press forming-process utilizing a press-forming device.
In the conventional heat exchanger having the above-described structure, the heat transfer members 103 are placed in parallel with each other at small intervals through the spacers 104 having a function of a gasket.
When there exists a large difference in pressure between heat exchange fluids, which flow along the opposite surfaces of the heat transfer member 103, the difference in pressure of the heat exchange fluids may deform the spacers 104, thus making it impossible to separate properly the heat exchange fluids from each other and leading to improper change in distance between the heat transfer members 103. Such problems may disenable heat exchange to be carried out effectively. In addition, there also exists a problem that a heat exchange fluid having a higher pressure cannot be introduced into a passage between the heat transfer members.